This is some example footage of the GNUnet Messenger running on the Pinephone Pro. The GUI application is implemented in C with GTK3 and libhandy to fit the mobile form factor. The responsive widgets also allow smooth navigation via swipe gestures.

More details about this application at my blog post here: https://thejackimonster.blogspot.com/2022/03/gnunet-messenger-api-march.html

Music: www.bensound.com